Color Doppler Imaging Determines Risk, Biomarkers in AMD

Fermin Rodrigo Auria, MD

A recent study measured and compared levels of plasmatic biomarkers in relation to vascular resistance alterations in the ophthalmic artery, central retinal artery, posterior temporal ciliary artery, and posterior nasal ciliary artery in patients with and without age-related macular degeneration (AMD).

Fermín Rodrigo Auria, MD, of the Department of Ophthalmology at Marina Baixa Hospital, in Villajoyosa, and the University of Castilla La Mancha, and colleagues, used color Doppler imaging to examine the relevant arteries, as well as peak systolic velocity, end-diastolic velocity, and Pourcelot resistive index. Participants also had a blood test for ascertaining plasmatic levels of homocysteine, C-reactive protein, B12 vitamin, and folic acid. Each patient underwent a complete ophthalmological exam and provided a detailed clinical history before the study.

The control group consisted of 30 patients with cataracts and the study group of 30 patients with naïve exudative AMD. According to the study authors, “Age‑related macular degeneration is the main cause of legal blindness in elderly people in developed countries.”

The study took a total of 30 eyes from 30 patients, included in both control and study groups, lacking significant differences between them in age (control: 75.33 ± 7.30 years, range 61—89 years; study: 78.60 ± 5.88 years, range 57–90 years; P = .061).

In the study group, 22 females (73.3%) and 8 males (26.7%) were included, and 14 females (46.7%) and 16 males (53.3%) were included in control group (P = .064), with no statistically significant differences realized between control and study groups in the percentage of eyes with arterial hypertension (P = .295), hypercholesterolemia (P = 1.00), cardiovascular disease (P = .671), brain vascular disease (P = .706), and treatment with statins (P = 1.00).

Every patient in the study group showed exudative AMD in one eye and intermediate AMD in the fellow eye. Concerning the eyes with exudative AMD, 20 (66.6%) showed angiographic features that were considered compatible with occult exudative AMD. In terms of classic examples of exudative AMD, 10 (33.3%) of the study patient showed features relative. “In the control group, any eye of each patient showed signs compatible with AMD or maculopathy associated with ag,” the authors wrote.

Researchers determined that there was a significant correlation in levels of C-reactive protein and Pourcelot resistive index in the group of patients with AMD (r = 0.498, P = .005). Pourcelot resistive index was increased in all arteries when compared with the control group, with a significant difference in PTCA (P = .035). Participants with AMD were also found to have significantly lower end-diastolic velocity in the central retinal artery compared with controls (P = .041).

The study group also exhibited significantly higher plasmatic levels of homocysteine (P = .042) and CRP (P = .046). The research team found no significant differences in folic acid or vitamin B12 between the two groups (P = .265; P = .520).

The researchers determined that these changes have an etiological effect on exudative AMD, and recommended further study: “Our patients with exudative AMD seem to have a general vascular disorder in all arteries evaluated,” they wrote. “This vascular compromise might be aggravated due to the increase in the plasmatic levels of homocysteine and CRP that would lead to a worsening of the vascular changes associated with age. Therefore, the decrease of the choroidal perfusion related to the hyperhomocysteinemia, and the increase in the plasmatic levels of CRP may have an etiological role on the exudative AMD. This should be confirmed in future studies with larger patient samples.”

The study, “Color Doppler imaging of the retrobulbar circulation and plasmatic biomarkers of vascular risk in age-related macular degeneration: A pilot study,” was published in the Indian Journal of Ophthalmology

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